Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N37/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having three bonds to hetero atoms with at the most two bonds to halogen, e.g. carboxylic acids
  • A01N37/18—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having three bonds to hetero atoms with at the most two bonds to halogen, e.g. carboxylic acids containing the group —CO—N<, e.g. carboxylic acid amides or imides; Thio analogues thereof
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
  • A01N25/02—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests containing liquids as carriers, diluents or solvents
  • A01N25/04—Dispersions, emulsions, suspoemulsions, suspension concentrates or gels
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N39/00—Biocides, pest repellants or attractants, or plant growth regulators containing aryloxy- or arylthio-aliphatic or cycloaliphatic compounds, containing the group or, e.g. phenoxyethylamine, phenylthio-acetonitrile, phenoxyacetone
  • A01N39/02—Aryloxy-carboxylic acids; Derivatives thereof

Definitions

• This invention relates to novel herbicide formulations.
• this invention relates to novel aqueous flowable concentrates of the herbicide 2-(a-naphthoxy)-N,N-diethyl propionamide.
• This herbicide whose common name is "napropamide,” and which is manufactured by Stauffer Chemical Company under the trademark DEVRINOL@, has the following structural formula
• the synthesis and utility of this compound are disclosed in U.S. Patent No. 3,480,671 (Tilles et al., November 25, 1969), U.S. Patent No. 3,718,455 (Baker et al., February 22, 1973), and U.S. Patent No. 3,998,880 (Mihailovski et al., December 21, 1976).
• Napropamide is a solid essentially insoluble in water and has been commercially available in the form of emulsifiable concentrates and wettable powders.
• the former is a solution of the herbicide and a surface-active compound in a water-immiscible or partially water-miscible solvent. When diluted with water, the solution forms an emulsion which is stabilized by the surface-active compound.
• Typical solvents for emulsifiable concentrates include mineral oils, petroleum products, chlorinated hydrocarbons, ethers, esters, and ketones. Unfortunately, a large amount of solvent is required, contributing substantially to the cost of the emulsifiable concentrate and accelerating the depletion of the natural resources from which the solvent was derived.
• Wettable powders are water-dispersible powders containing the herbicide, an inert solid filler, and one or more surface-active agent to enhance wetting and prevent heavy flocculation when suspended with water.
• Typical solid fillers include natural clays, talcs, diatomaceous earth, and synthetic mineral fillers derived from silica and silicate. Unfortunately, it is difficult for the user to avoid contact with wettable powders during handling and mixing due to the dusty nature of the powders.
• Flowable formulations require little or no organic solvent and offer a greatly reduced possibility of user contact.
• Flowables are concentrated suspensions of a solid pesticide in an aqueous system. Having the characteristics of a thick liquid, a lowable formulation can be poured from a container, pumped, or otherwise transferred as any other viscous liquid. When the user is ready to apply the herbicide, he merely dilutes the flowable with water to the desired concentration and applies it to the field.
• the optimum flowable formulation is one which demonstrates little or no settling and yet has a viscosity low enough to permit mixing and handling with reasonable ease.
• the optimum flowable will also have little susceptibility to syneresis whereby a thin liquid separates from the rest of the mixture, or to grit formation caused by the aggregation of the solid herbicide particles, particularly upon freezing and subsequent thawing of the suspension.
• a still further object of this invention is to provide a method of controlling undesired vegetation by applying to the locus where control is desired an aqueous dispersion of an herbicidally effective amount of 2-(a-naphthoxy)-N,N-diethyl propionamide formed by diluting the aqueous flowable concentrate of the present invention with water.
• the present invention resides in two major discoveries. The first is that different combinations of the ingredients used in conventional flowable formulations of other herbicides give rise to widely differing results when combined with napropamide. The second is that a particular combination of ingredients produces a flowable formulation of unexpectedly superior properties.
• a water-based flowable napropamide formulation of superior stability and rheological properties can be obtained by combining the following components in the proportions stated: The above components are combined to form a dispersion and then milled such that the average particle size of the solids ranges from about 5 to about 15 microns, preferably from about 5 to about 10 microns.
• the formulation may also contain additional components for further improvements in its properties, for example: viscosity modifiers, deflocculating agents, thixotropy modifiers, and syneresis control agents. These are discussed in detail below.
• the smectite clays which are useful in the present invention include both the naturally-occurring and the synthetic smectites.
• the term "smectite” is commonly used to denote a group of expanding clays which are derived from pyrophyllites and talc by substitution of various metallic atoms in the clay structure. Specifically, the term “smectite” refers to minerals in the lower substitution ranges, to distinguish from the higher charge vermiculites. Examples of smectite clays are montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite, and bentonite.
• clays can be prepared synthetically by either a pneumolytic or hydrothermal synthesis.
• the preferred technique is the hydroxothermal synthesis, in which hydrous oxides or hydroxides of the desired metals are placed in an aqueous slurry with sodium fluoride in proportions corresponding to those of the desired product. The slurry is then heated in an autoclave under autogenous pressure to 100° to 325°C until a product of the desired composition is formed. Further discussion and descriptions of smectites may be found in "Rocking Forming Minerals," Vol. 3, Sheet Silicates, By W. A. Deer et al., London 1962, pp. 226-245.
• the nonionic surfactant of the present formulation serves primarily as a wetting agent.
• Suitable nonionic surfactants include all such water-soluble substances known to those skilled in the formulations art. Examples include long-chain alkyl and mercaptan polyalkoxy alcohols, alkylaryl polyalkoxy alcohols, sorbitan fatty esters, polyoxyethylene ethers, polyoxyethylene glycol esters, and polyoxyethylene esters of fatty and resin acids, was well as mixtures of the above.
• Preferred surfactants are the polyalkoxy alcohols.
• the dispersant used in the present informulation can be any of the water-soluble materials well known to act as dispersants for finely divided solids in water.
• examples of such materials are low-viscosity methyl cellulose, water-soluble low-viscosity partially hydrolyzed polyvinyl alcohol, polyoxyethylene sorbitan esters of mixed fatty acid rosin acids, purified sodium lignin sulfonates, sodium salts of polymerized alkaryl and aryl alkyl sulfonic acids, methyl hydroxyethyl cellulose, and carboxymethyl cellulose.
• Preferred dispersants are the sodium lignin sulfonates.
• the freezing point depressant can be antifreeze or any other water-soluble substance which serves to lower the freezing point of water to an extent proportional to its molar concentration.
• Examples are low molecular weight glycols and alcohols such as ethylene glycol, propylene glycol, methanol, and isopropanol; ureas; and salts such as alkali and alkaline earth halides.
• the glycols are preferred.
• xanthan gums polymethylvinyl ether/maleic anhydride mixtures, carboxy vinyl polymers, and nonylphenoxy polymers are useful as thickening agents; sodium mono- and dimethyl naphthalene sulfonates and the like are useful for raising the thixotropic index; and pregelatinized starch and other polymers serve to decrease the occurrence of syneresis.
• the napropamide is preferably milled in a hammermill or airmill to a particle size ranging from about 30 microns to about 5 millimeters in diameter prior to being combined in a pre-slurry with the other components of the formulation. Once the pre-slurry is formed, it is then further milled to reduce the solid particle size to the desired range of about 5 to about 15, preferably about 5 to about 10 microns. Ball mills, media mills, and colloid mills are examples of means effective for this final size reduction.
• the seventh component was added to the first six slowly with mixing provided simultaneously by a high-speed Cowles blade. Once the addition was complete, the resulting slurry was ball-milled for 17 hours.
• the result was a flowable concentrate with particle size ranging from 1 to 16 microns, and an average particle size of 5 microns, as measured by an electrical resistance method on a Coulter Counter.
• the concentrate was diluted was diluted with water and displayed spontaneous dispersion in the added water.
• a sample of the concentrate was cooled to -12°C for three hours and remained fluid throughout.
• a further sample was frozen solid in an acetone bath at -40°C. Upon subsequent thawing, the sample appeared smooth and homogeneous, i.e., no grits (aggregated napropamide particles) were observed.
• the thawed sample was then frozen and thawed three more times at -15°C to -20°C, after which it still remained smooth and homogeneous.
• This formulation differs from that of Example 1 by the substitution of propylene glycol for ethylene glycol, the elimination of the anti-foaming agent, and the use of dry smectite clay, as well as a lower concentration of napropamide.
• the solid components were added to the liquid components and the resulting slurry was ball-milled down to an average particle size of 10 microns.
• the concentrate Upon dilution with water, the concentrate displayed spontaneous dispersion.
• a sample of the concentrate was frozen and thawed three times in succession, in the same manner as that described in Example 1, and the result was a smooth and homogeneous dispersion, with no grit formation.
• a further sample was heated to 43°C for 6 hours, showing no change in appearance.
• a still further sample was stored undisturbed at ambient temperature for 7 days, at the end of which time a slight degree of syneresis and sediment formation was observed, both of which were easily eliminated with slight manual shaking.
• an attapulgus-type clay is used in place of a smectite-clay.
• the result is a flowable concentrate of substantially less stability, as the following description shows:
• the ingredients were combined in a slurry which was milled in a ball mill for six hours. The result was a dispersion with a pasty consistency. An additional 8 g of Lomar PWA and 8 g of Polyfon H were then added, together with additional water. The dispersion was now of a much more fluid nature and it was milled in a ball mill overnight.
• the resulting dispersion had an average particle size of 7.2 microns and showed no sedimentation upon standing. After one freeze thaw cycle, however, a sample of the dispersion became gritty, i.e., napropamide particles had aggregated. When heated to 43°C, sedimentation occurred.
• an anionic surfactant is used in place of a nonionic surfactant as a wetting agent.
• the result is a flowable concentrate with lesser stability, particularly upon freezing.
• the slurry was milled for about six hours to produce a dispersion which dispersed readily and spontaneously when diluted with water. After two freeze-thaw cycles, however, grits appeared in the dispersion.
• formulations within the scope of the present invention are more stable with regard to sedimentation and grit formation upon freezing and thawing.
• Example 1 To demonstrate the herbicidal activity of the formulations of the present invention, the formulation prepared in Example 1 was evaluated in a pre-plant soil incorporation test as follows:
• Additional soil samples were treated in a similar manner using two current commercial formulations of napropamide - an emulsifiable concentrate and a wettable powder - for comparison testing in separate flats.
• the soil was placed in a 6-inch (15.2 cm) by 9-inch (22.9 cm) by 2.75-inch (7.0 cm) fiber planting flat.
• An amount of soil equivalent to a depth of 0.5-inch (1.3 cm) was removed and seven rows were impressed across the width of the flat.
• Each row was seeded with a single weed species.
• Ample seeds were planted to produce about 20 to 50 seedlings per row, the actual number in each row depending on the size of the plants in an untreated flat at the rating time.
• the seeds were then covered with the soil previously removed and the flats were placed in a greenhouse where they were watered daily and maintained at a temperature of 70-85°F (21-29°C).
• the degree of control was estimated by a visual comparison of treated flats with untreated flats.
• the degree of control in the treated flats was expressed as a percentage, using the untreated flats as a reference.
• 0% represents no injury (i.e., growth comparable to that in an untreated flat) and 100% represents complete kill of the entire row.
• the results are shown in the table below.
• the term "herbicide” denotes a compound which controls or modifies the growth of plants.
• the term “herbicidally effective amount” is used to indicate any quantity of such a compound or a formulation of such a compound which is capable of producing such an effect. Controlling or modifying effects include all deviations from natural development, for example: killing, retardation, defoliation, desiccation, regulation, stunting, tillering, stimulating, leaf burn, dwarfing and the like.
• plants is intended to include germinating seeds, emerging seedlings, and established vegetation, including roots and above-ground portions.
• the present flowable concentrate is diluted with water prior to application to the field.
• the dilution is conveniently done at the field site in a tank where agitation is provided to hasten the dispersion of the concentrate and to ensure a homogeneous mixture.
• the degree of dilution will be selected by the operator, whose decision will be based on the particular weeds to be controlled and the degree of control desired.
• sufficient water will be added such that the final dispersion will contain from about 0.01 to about 5.0 kilograms napropamide per liter of dispersion, preferably from about 0.1 to about 1.0 kilograms per liter.
• Field application can be accomplished by any conventional technique designed for applying liquids. Spray techniques are particularly useful, ranging from boom sprayers, and hand sprayers to airplane sprayers.
• the locus of application can be soil, seeds, seedlings, or the actual plants, as well as flooded fields.
• Field application can also be accomplished by addition of the flowable concentrate or a diluted dispersion to irrigation water immediately before or while the latter is being supplied to the field.
• the application rate will be determined by the same factors mentioned in the preceding paragraph, and generally ranges from about 10 to about 1000 liters per hectare, preferably from about 50 to about 500 liters per hectare.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Wood Science & Technology (AREA)
• Plant Pathology (AREA)
• Engineering & Computer Science (AREA)
• Dentistry (AREA)
• Pest Control & Pesticides (AREA)
• Agronomy & Crop Science (AREA)
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• Dispersion Chemistry (AREA)
• Toxicology (AREA)
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• 1979
  • 1979-10-29 US US06/089,070 patent/US4266965A/en not_active Expired - Lifetime
• 1980
  • 1980-10-23 IL IL61334A patent/IL61334A/xx unknown
  • 1980-10-24 TR TR21089A patent/TR21089A/xx unknown
  • 1980-10-24 GR GR63218A patent/GR70769B/el unknown
  • 1980-10-27 AR AR283015A patent/AR224280A1/es active
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  • 1980-10-28 AU AU63761/80A patent/AU533004B2/en not_active Ceased
  • 1980-10-28 NZ NZ195379A patent/NZ195379A/xx unknown
  • 1980-10-28 PT PT71984A patent/PT71984B/pt unknown
  • 1980-10-28 KR KR1019800004122A patent/KR850000220B1/ko active IP Right Grant
  • 1980-10-28 ZA ZA00806610A patent/ZA806610B/xx unknown
  • 1980-10-28 MA MA19183A patent/MA18983A1/fr unknown
  • 1980-10-28 GT GT198066065A patent/GT198066065A/es unknown
  • 1980-10-28 CA CA000363435A patent/CA1134637A/en not_active Expired
  • 1980-10-29 EP EP80201029A patent/EP0028052B1/en not_active Expired
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  • 1980-10-29 JP JP15086580A patent/JPS5686101A/ja active Pending
  • 1980-10-29 DE DE8080201029T patent/DE3061694D1/de not_active Expired
  • 1980-10-29 AT AT80201029T patent/ATE2250T1/de not_active IP Right Cessation
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